MTX Doubles Hepatotoxicity Risk in Psoriasis Patients

The risk of incident liver disease doubled when patients with psoriasis (PsO) or psoriatic arthritis (PsA) received methotrexate (MTX), but not when MTX was used in rheumatoid arthritis (RA), according to researchers from the University of Pennsylvania Perelman School of Medicine.

The comparative cohort study, published in the Journal of Investigative Dermatology, included patients with PsO (N=197,130), PsA (N=12,308), and RA (N=54,251), as well as matched controls (N=1,279,754). The team calculated the adjusted hazard ratios for any liver disease in these patients with or without systemic therapy. Liver disease was defined as any liver disease, non-alcoholic fatty liver disease (NAFLD), and cirrhosis of any etiology.

Overall, 6% of PsO patients were prescribed systemic therapy, as were 53% of people with PsA and 61% of those with RA. MTX was the most commonly prescribed systemic therapy.

Incident NAFLD was highest in patients with PsO prescribed systemic therapy (2.23) and PsA with systemic therapy (2.11). The risk of cirrhosis was highest among patients with PsO receiving systemic therapy (2.62) and PsA without systemic therapy (3.15).

Increasing body surface area in PsO further increased the prevalence of liver disease and cirrhosis (P for trend <0.001).

More so than RA, PsO and PsA are associated with liver disease, particularly NAFLD and cirrhosis, and this was true even among patients without systemic therapy exposure.

Compared with people without chronic inflammatory diseases, those with PsO in the study were 37% more likely to develop liver disorders. When such patients took MTX, they had roughly twice (67%) the odds of liver damage. For RA, there was no increased risk of liver disease when people took MTX, but when they didn’t, they had a 49% higher odds of liver damage.

The authors noted that there was no data on deaths from liver disease in this study.

Jack Cush, MD, is the director of clinical rheumatology at the Baylor Research Institute and a professor of medicine and rheumatology at Baylor University Medical Center in Dallas. He is the executive editor of RheumNow.com. A version of this article first appeared on RheumNow, a news, information, and commentary site dedicated to the field of rheumatology. Register to receive their free rheumatology newsletter.